Increases in airplane traffic have increased safety concerns, especially around crowded airports and terminals. It is therefore important to provide to an aircraft pilot Cockpit Display of Traffic Information (CDTI), which should present as accurate a picture as possible regarding the position of traffic elements, such as other aircraft, in the area. Several technologies have been developed that may be used to provide real-time positional information and other traffic data for airport surface and terminal area operations. The types of technology available to the modern flight deck may include Automatic Dependent Surveillance-Broadcast (ADS-B), Traffic Information Services-Broadcast (TIS-B), and onboard Traffic Collision and Avoidance System (TCAS) receivers.
One problem with using different types of technology to provide position information traffic elements is that each type of technology has its own accuracy and integrity, which leads to an inherent uncertainty in the true position of the traffic elements. What is needed is a method of communicating the position and positional uncertainty of nearby traffic elements to a pilot of an aircraft.
Another challenge is that there is only a limited amount of display space available for communicating to a pilot the positional uncertainty of nearby traffic elements. If not done properly, adding positional uncertainty to an otherwise information-rich display may run the risk of unnecessarily cluttering up the display space, thereby making it more difficult for a pilot to ascertain necessary information.
It is therefore an object of the invention to provide a method for integrating information obtained from different types of positioning technology to determine the position of a traffic element such as an aircraft.
It is a further object of the invention to provide a method for deriving, from a plurality of different types of positioning technologies, a positional uncertainty of a nearby traffic element.
It is a further object of the invention to increase the situational awareness of a pilot by communicating the position and positional uncertainty of nearby traffic elements in a manner that is easily ascertainable, without unduly cluttering the display space.
A feature of the invention is a geometric figure, overlaid on a depiction of a nearby traffic element on a display, where the geometric figure expresses the combined positional uncertainty of the traffic element as derived from a plurality of positioning technology inputs.
An advantage of the invention is an easily readable symbology scheme that increases situational awareness of a viewer without increasing clutter in the displays space.